Gas barrier laminated film and process for producing the same

Abstract

There are provided a gas barrier laminated film, which is transparent while possessing excellent gas barrier properties and, at the same time, has excellent impact resistance, and a process for producing the same. The gas barrier laminated film comprises a base material, a vapor deposited film of an inorganic oxide provided on the base material, and a gas barrier coating film provided on the vapor deposited film. The gas barrier laminated film is characterized in that the base material on its side where the vapor deposited film is provided, has been subjected to pretreatment or primer coating treatment, and the gas barrier coating film has been formed by coating a gas barrier coating liquid onto the inorganic oxide film and then heating the coating.

1. A gas barrier laminated film comprising a base material, a vapor deposited film of an inorganic oxide provided on the base material, and a gas barrier coating film provided on the vapor deposited film,
 wherein said base material on its side where the vapor deposited film is provided, has been subjected to pretreatment or primer coating treatment, 
 wherein said gas barrier coating film has been formed by coating a gas barrier coating liquid onto the inorganic oxide film and then heating the coating, 
 wherein the vapor deposited film is composed mainly of silicon oxide and further contains, through a chemical bond, at least one compound comprising one or more elements of carbon, hydrogen, silicon and oxygen, and 
 wherein the content of the compound is reduced from the surface of the vapor deposited film in the thickness direction thereof toward the base material. 
 
     
     
       2. The gas barrier laminated film according to  claim 1 , wherein the vapor deposited film has been formed by chemical vapor deposition. 
     
     
       3. The gas barrier laminated film according to  claim 2 , wherein the vapor deposited film formed by the chemical vapor deposition has a structure comprising two or more silicon oxide layers each formed by plasma chemical vapor deposition in such a manner that at least two film formation chambers are used and, for respective chambers, two or more mixed gas compositions for film formation comprising at least: a monomer gas for film formation comprising one or more organosilicon compounds; an oxygen gas; and an inert gas, the two or more mixed gas compositions being different from each other in mixing ratio of the gas components, are used, and the each silicon oxide layer contains carbon atoms in its layer and the carbon content varies from layer to layer. 
     
     
       4. The gas barrier laminated film according to  claim 1 , wherein the vapor deposited film has been formed by physical vapor deposition. 
     
     
       5. The gas barrier laminated film according to  claim 1 , wherein the base material is formed of a biaxially stretched polyester resin film, a biaxially stretched polyamide resin film, or a biaxially stretched polyolefin resin film. 
     
     
       6. The gas barrier laminated film according to  claim 1 , wherein the pretreatment for the base material is glow discharge treatment, plasma treatment, corona treatment, or microwave treatment. 
     
     
       7. The gas barrier laminated film according to  claim 6 , wherein oxygen, argon, nitrogen, helium gas, or a mixed gas composed of two or more of them is used for the pretreatment. 
     
     
       8. The gas barrier laminated film according to  claim 1 , wherein the primer coating treatment for the base material is carried out by coating a coating liquid comprising a polyester resin, an acrylic resin, a urethane resin, and an isocyanate curing agent onto the base material. 
     
     
       9. The gas barrier laminated film according to  claim 1 , wherein the vapor deposited film on its side where the gas barrier coating film is formed, has been subjected to post treatment, and the post treatment is glow discharge treatment, plasma treatment, or microwave treatment. 
     
     
       10. The gas barrier laminated film according to  claim 1 , wherein the gas barrier coating film is formed of a hydrolyzed condensate of an alkoxide or a hydrolysate of an alkoxide produced by polycondensing, by a sol-gel process, a composition comprising one or more alkoxides represented by general formula R 1   n M(OR 2 ) m  wherein M represents a metal atom; R 1  and R 2  represent an organic group having 1 to 8 carbon atoms; n is an integer of 0 (zero) or more; m is an integer of 1 or more; and n+m represents the valence of M, a polyvinyl alcohol and/or ethylene/vinyl alcohol. 
     
     
       11. The gas barrier laminated film according to  claim 10 , wherein the composition further comprises a silane coupling agent. 
     
     
       12. The gas barrier laminated film according to  claim 1 , wherein the gas barrier coating film has a structure of a plurality of layers. 
     
     
       13. The gas barrier laminated film according to  claim 1 , wherein a vapor deposited film of an inorganic oxide is further provided on the gas barrier coating film provided on the vapor deposited film, and the gas barrier coating film is provided on the vapor deposited film. 
     
     
       14. A laminated material for packaging, comprising a gas barrier laminated film according to  claim 1 , characterized in that a heat sealing resin layer is provided on the gas barrier coating film in the laminated film. 
     
     
       15. The laminated material for packaging according to  claim 14 , wherein the gas barrier coating film and the heat sealing resin layer are laminated onto each other by melt extrusion through a primer layer and a melt extruded resin layer. 
     
     
       16. The laminated material for packaging according to  claim 14 , wherein the heat sealing resin layer is formed of a polyolefin resin. 
     
     
       17. The laminated material for packaging according to  claim 14 , wherein an intermediate base material is provided between the gas barrier coating film and the heat sealing resin layer. 
     
     
       18. A packaging bag using a laminated material for packaging according to  claim 14 , the packaging bag comprising two laminated materials for packaging superimposed onto each other so that the heat sealing resin layer side of one of the laminated materials for packaging faces the heat sealing resin layer side of the other laminated material for packaging, the end part of the assembly having been heat sealed. 
     
     
       19. The gas barrier laminated film according to  claim 1 , wherein the surface of the inorganic oxide film is subjected to a plasma treatment, and the surface tension of the surface of the inorganic oxide film is not less than 54 dyne/cm. 
     
     
       20. A process for producing a gas barrier laminated film according to  claim 1  comprising the steps of:
 providing a base material and subjecting one side of the base material to pretreatment or primer coating treatment, 
 forming a vapor deposited film of an inorganic oxide on the treated surface of the base material, 
 subjecting the surface of the vapor deposited film of an inorganic oxide to plasma treatment, and 
 coating a gas barrier coating liquid onto the vapor deposited film and heating the coating at 180 to 200° C. for 0.005 to 60 min. to form a gas barrier coating film. 
 
     
     
       21. The process according to  claim 20 , wherein the vapor deposited film has been formed by chemical vapor deposition. 
     
     
       22. The process according to  claim 21 , wherein the vapor deposited film formed by the chemical vapor deposition has a structure comprising two or more silicon oxide layers each formed by plasma chemical vapor deposition in such a manner that at least two film formation chambers are used and, for respective chambers, two or more mixed gas compositions for film formation comprising at least: a monomer gas for film formation comprising one or more organosilicon compounds; an oxygen gas; and an inert gas, the two or more mixed gas compositions being different from each other in mixing ratio of the gas components, are used, and the each silicon oxide layer contains carbon atoms in its layer and the carbon content varies from layer to layer. 
     
     
       23. The process according to  claim 20 , wherein the vapor deposited film has been formed by physical vapor deposition. 
     
     
       24. The process according to  claim 20 , wherein the pretreatment for the base material is glow discharge treatment, plasma treatment, corona treatment, or microwave treatment. 
     
     
       25. The process according to  claim 24 , wherein oxygen, argon, nitrogen, helium gas, or a mixed gas composed of two or more of them is used for the pretreatment. 
     
     
       26. The process according to  claim 20 , wherein the primer coating treatment for the base material is carried out by coating a coating liquid comprising a polyester resin, an acrylic resin, a urethane resin, and an isocyanate curing agent onto the base material. 
     
     
       27. The process according to  claim 20 , wherein the plasma treatment is carried out until the surface tension of the surface of the inorganic oxide film becomes not less than 54 dyne/cm.